Fluid compressor



June 21, 1932. H B HALVORSEN 1,863,845

' FLUID COMPRESSOR Filed April 22, 1929 Patented June .217, 1932 UNITED STATES PATENT or-rice HALBERT B. HALVORSEN, OF MICHIGAN CITY, NDIANA, ASSIGISTOR T0 ACHINERY COMPANY, A CORPORATION OF MSSACHUSETTS'- sULLivAN MAQ FLUID COMPRESSOR Application ledApril 22,

of deviceson each cylinder for effecting unloading of both. cylinders almost simultaneously. It will therefore be noted that when the high pressure cylinder is` unloaded at the same time as the low pressure cylinder., the compressed' air or gas in the mtercooler will be lost. With my improvedunloading mechanism the unloading device proper` for the high pressure cylinder isnot operated until a certain time after the low pressure cylinder is unloaded, thereby giving'the high pressure cylinder a chance to pump outthe fluid from the intercooler. Thus the energy which is stored in the compressedriuid in the intercooleris not lost. Other objectsand advantages of my invention will appear dur-A i ing the course of the following specification and claims. l n

My invention preferably contemplates unloading devices for the high and low presi sure cylinders which are actuated tounloading position by fluid pressure, and a pressure responsive pilot valve for controlling the supply and exhaust of pressure fluid to and from suchdevices, the connection leading rom the pilot valve tothe high pressure unloading deviceembodying means-for delaying the building up of pressure on the high pressure unloading device until a certain time aftertlier low pressure cylinder unloader'has been operated. Preferably also` means areeprovidedfor restricting the How of pressure fluid between the pilot valvek and high pressure unloader in one. directionand allowing a relatively free iow inthe other f direction, wherebythe unloading function is l se effected differently,

1929; SerialNo. 357,179.

delayed,` while permitting a` quickre'verse4 operation to-caiise loading. In one preferred embodiment I. have connected a tank andf one-way valve having a restricted port therethrough in the line leading from the pilot valve to the high pressure cylinder unloader. Obviously, however, means maybe built into the pilot valve .for causing the delayed sup ply of fluid to thisJ capacity of the pipe leading from the p1 otications are clearly within thek scope of my invention as will be readily apparent to those skilled in the art, and it invention in its broader the high pressure cylinder, or

valve may be suiiicieiitto allow doingl away with the tank. These and other modi'- will be noted that the aspects can be pra'cticedin other systems7 for eXample,siich as.-

effect unloading by venting pressure and loading by its supply: in such case providing delayedv ventinglof the higher stage unloading device.' Moreover, the unloading ofthe high pressure cylinder may be delayed-,but actuation ofA the unloading mechanism` per as by a pressure switch controlled solenoid. i

In the accompanying drawing I have.

shownV for purposes of illustration one pre,-

ferred embodiment of my invention. j

I In the drawing, ,n Y f Fig. l represents a diagrammatic View of v a compressor system having my improved iin-,

loading` means associated therewith;

Fig. :2 is also-a diagrammatic view with some partsshown in section, illustrating the construction ofl some of the elements of lmy invention andthe various pipe connections.

Y Fig. Slisa fragmentary view looking in the direction of arrows 3, Sin Fig. l.

Fig. 4 isa central vertical section through i tliehigh pressure relief valve mechanism.

In Fig. l there is shown a compressor of the angle compound type having a low pressure cylinder. 6y arranged horizontally. anda high pressure cylinder 7 arranged vertically. An intercooler 8 is interposed between the two cylinders 'which will be understood to have capacity for a considerable volume of compressed iiuid. The high pressure cylinder isconnectedthrough a discharge p'1pe9 toa suitable receivertank 10i from which coniico e if pressed liuid may be suppliedzfor anyA desired purpose. A fluid actuated unloading device 11, which is herein shown as being of the total closure intake type, is connected to the low pressure cylinder. As shown in Fig. 2, theV interior of this unloader embodies a longitudinally movable valve 12, connected to a piston 13 reciprocating in a cylinder meinber 14 arranged directly above the main valve casing. lVhen the valve is closed by the ap'- plication of pressure on piston 13, the intake for the low pressure cylinder is cut olf, thereby' causing unloading of the same. The valve and piston are normally held in. their upward or unloaded position by means of a spring 15 arranged in. cylinder member 14'v below the piston. For the purpose of supplying' and exhausting pressure Vfluid to and from cylinder member 14to cause loading and unloading in response to pressure in the receiver tank, a pilot valve mechanism 16 of suitableconstruction is connected to the receiver -tank by a pipe 17 and the cylinder 14 by pipes 18,19. The pilot valve, which I have shown merely in outline, since its construction and operation areknown in the art, is the `well known Penn pilot valve which operates when there is a'4 I predetermined highpressure in the receiver' tank to open a connection between pipes 17 and 18, and when there is a predeterminedV low pressure in the receiver tank, to close'oif' .pipe 17 and connect pipe `18 to a vent leading to theatmosphere. y e

The high pressure cylinder relief valve mechanism is of the same type as disclosed in a copending applicationof W. E. Hughes,

Serial No. 326,807, iiled Dec. 18, 1928, now'v No. 1,786,114, patented Outwardlyq opening 'checkmatured into Patent Dec. 23, 1930. u valves 20 and 21 are connected to opposite ends of the cylinder'andthese'check valves lead to a common connection 22 through which both ends ofthe cylinder*mayVb'e-vented'by means of the vent valve mechanism 23. :In the latter mechanism is -a valvefelement' 24 adapted tofbe opened byv pressureon the diazphragm -25 and closed by means-of spring when pressure Aon the diaphragm is relieved. When this valve is closed, as when itis desired to load the compressor, a high pressure will very quickly after hold the check valves/closed and permit the cylinder to function normally. When valve 24 is opened to unload the compressor,

both ends of the high pressure cylinder are vented directly to atmosphere through valves 'f 20,21 and 24. Now in order best to control the high and low pressure unloaders with the The check valve'28 is so connected that the valve element 31 will opentowardV the pilot l assume in practice, it willfbe understood that build up betweenthe check valves and the relief valve which will there- Y of the relief valve mechanism.23.A n e e y l the high pressurel cylinderv a substantal time pressure Vis reached in the vreceiver tank, the

pilot valve will operate to establish connection between pipes 17 and 18.y Pressure fluid will flow freely to cylinder 1,4 and cause unloading of the -low pressure cylinder. Fluid also flows'through the restricted port 32 into tank 29, where a pressure is gradually built up.

This pressure is transmitted to the diaphragm chamber of the high pressure relief valve mechanism 23. When a sui'iicient pressure has built up to 'ov'erbalancethe spring 26,athe highpressure relief lvalve'is opened,l but during the interval between closing of 'thelow pressure intake unloaderand openingofthe high 'pressure relief valve the high' pressure piston which-'has continued to reciprocate has pumped out the fluid under intermedi-i ate pressure in the intercooler 8. rEhere'fore, f when the high pressure relief is finally' opened, practically no energy is lost yby reasonof venting the'intercooler to the atmosphere..x Now in the'reverse operation, whenav prede--Y termined low pressure vis reached in the-re-r4 ceiver tank, the pilot valveventsthe linej18 andpermits the pressure iiuid in cylinder'14f to be exhausted, thereby causing loading of" the lowpressure cylinder. Simultaneously' the diaphragm chamber-of the high pressure relie-f valve mechanism' afndtank'29 are alsoy vented through pipe`18' and, in/vie'w ofthe `fact Ythat the check valve '31 willat this time and that no partially compressed air wi-llbe I thrown away. It will-also be noted that'tlie improved controlling :mechanism lends itself to embodiment inl 'existing systems-,to ,pro-:1 vide animproved and more efficient control.-l vVhile' I have in thisapplication Vspecifically y, desciibedone form which my inventionmay' 1. In combinationwith a compound "com-y pressor, an unloader forthe low pressure cylf Vvinder, adevice controlling the unloader, un-

loading means for Vthe high pressure cylinder-i also connectedV to: `said" device for control thereby, and means for delaying unloading of 2. In combination with a compressor having a plurality of cylinders, a fluid actuated unloader for each of the cylinders, a pilot valve responsive to compressorV discharge pressure, and connections from said pilot valve to said unloaders, one `of said connections including means for causing a substantial delay between movement ot said pilot valve and the actuation of the unloader with which said connection communicates.l

3. In combination with a compressor having a plurality of cylinders. a fluid actuated unloader for each of the cylinders, a pilot valve responsive to compressor discharge pressure, connections from said pilot valve to each of said unloaders, and means in one of said connections for restricting the flow of fluid in one direct-ion to cause a substantial delay between movement of said pilot'valve and actuation of the unloader withv which said connection communicates. Y

4. In combination with a compressor having a plurality of cylinders, fluid actuated unloaders for the cylinders, a pilot valve responsive to compressor dis-charge pressure,

connections from said pilot valve to each of said unloaders, and a tank interposed in one of said connections whereby a substantial delay occurs between movement of the pilot valve and actuation of the unloader with which said last mentioned connection communicates.

5. In combination with a compound compressor, a iluid actuated unloader for the low pressure cylinder, a pilot valve responsive to compressor discharge pressure for controlling said unloader, fluid actuated means for unloading the high pressure cylinder also connected to said pilot valve for control thereby, and means for delaying unloading of the high pressure cylinder for a substantial time after unloading of the low pressure cylinder.

6. In combination with a compound coinpressor, afluid actuated unloader for the low pressure cylinder, a pilot valve responsive to compressor discharge pressure for controlling said unloader, fluid actuated means for unloading the high pressure cylinder also connected to said pilot valve Jfor control thereby, and a delay tank interposed in the connection leading from the pilot Vvalve tothe high pressure unloaderfor causing a substantial delay between unloading of tlie'low pressure cylinder and theihigh pressure cylinder.

7. In combination withv a compound compressor, a fluid actuated unloader for the low pressure cylinder, a pilot valve responsive to compressor discharge pressure for controlling said unloader, iiuid actuated means tor unloading the high pressure cylinder also connected to said pilot valve for control thereby, and means in the connection leading from the pilot valve to the high pressure cylinder unloader for restricting the iiow ,of

pressure fluid in-one direction to cause ,a substantial delayin the unloading ot the high pressure cylinder, a pilot valve responsive toy compressor discharge pressure for vcontrolling said unloader, fluid actuated-means for unloading the hi h pressure cylinder also connected to said pilot valve for control thereby, means in said connection for restricting the rate of How ol pressure duid in one direction between the pilot valveand high pressure unloaderfand a delay tank interposed in the connection leading tromthe pilot valve to the high pressure unloader, said vtlowrestricting means and delay tank constituting means for causing a substantial delay between unloading of the low pressure cylinder and the high pressure cylinder. y

9. In combination with a compound compressor,a fluid actuated unloader for the low pressure cylinder, a pilot valve responsive to compressor discharge pressure for controlling said unloader, fluid actuated means for unloading the high pressure cylinder also connected to said pilot valve for control thereby, an automatic one-way valve in the connection leading from the pilot valve to the high pressure unloadei, and means permitting a restricted flow of iiuid past said valve even when `closed whereby unloading of thehigh pressure cylinder is delayed for a substantial time after unloading of the low pressure cylinder and whereby loading of the two cylinders occurs simultaneously. l

l0. In combination with a compound compreSsor, a device 'for unloading the low ypressure cylinder when subjected to pressure, a device for unloading the high pressure cylinder when subjected to pressure, a pilot valve responsive to compressor discharge pressure for controlling supply of pressure fluid to said devices, connections between said pilot valve. and said devices, a delay tank interposed inthe connection leading from the pilot valve to the high pressure unloader, a check valve opening toward the pilot valve also in the connection leading from the'pilot valve to the high pressure unloader, and a restricted port through said check valve permitting a restricted flow toward thev high pressure unloader when the check valve is closed.

1l. In combination with a compound compressor, an unloading mechanism for the low pressure cylinder, an unloading mechanism for the high'pressure cylinder, pressure responsive pilot means controlling both of said mechanisms, and means intermediate said pilot means and said high pressure unloading mechanism for delaying the operation of the latter 'until a material time after `operation of the-low pressure unloading mechanism.

12. In combination with a compound compressor having low and high pressure cylin-` ders, pressure Huid operableunloading mechv anism for the loW pressure cylinder7 pressure fluid operable unloading mechanismk for'the high pressure cylinder, compressor discharge pressure responsive means l'for ,controlling pressure iuid flow towards and from both of said unloading mechanisms, and fluid con-k ducting means for connecting said compres- 10 sor discharge pressure responsive means with said unloading mechanisms including between the compressor discharge pressure responsive means and the unloading mechanism for the high pressureV cylinder means for retarding y V fluid flow toward said unloading mechanism but not reverse flow relative thereto.

In testimony whereof I atlix my signature.

` I-*IALBIER'YI B. HALVORSEN. 

